Draft gear



M. B. HALL 2,079,011

' DRAFT GEAR l Filed sept. 2e, 1954 2 sheets-sheet 1 `Maly 4, 1937.

Jz 2'2 J6' May 4, 1937. M. B. HALL DRAFT GEAR Filedsept. 26, 1954 Patented May 4, 1937 UNITED STATES PArNTk OFFICE Application September 26, 1934, Serial No. 745,499

6 Claims.

This invention relates to shock absorbing mechanism, and, more particularly, to draft gears for railway cars, of the friction type. l

One of the objects of the invention is the provision of a new and improved `draft gear having a novelv arrangement and construction of the wedging mechanism.

Another object of the invention is the provision of `anew and improvedV draft gear having the wedging mechanism'so constructed that thel gear has a maximum 'extent of friction surfaces with a resultant minimum amount of wear.

A further object of the invention is the provision of va new and improved gearghaving a maximum capacity and so constructed that the follower casings will resist abnormal shocks without becoming distorted or broken.

A still further yobject of the invention is the provision. of a new and improved gear having novel followercasings so constructed that they will receive a maximum capacity spring assembly and wedge mechanism, and at the same time providean exceedingly strong column to resist abnormal buffingl thrusts when the gear goes solid.

Another object of the invention is the provision of a new and improved draft-gear having novel follower casings provided with a novel arrangement and means for `connecting the housings together.

A further object of the invention is the provision ofv a newV and improved draft gear which is simple in construction, of high capacity, eflicient in operation'and which is not likely to become fio i-njuredor distorted when the gear goes solid.

Other and further objects and advantages of the invention will appear from thefollowing description taken in connection with the accompanying drawings, in which Fig. 1 isa horizontal section of the center sills of a railway car showing the invention in expanded position therein, with parts in section and parts broken away;

I Fig. 2 is a horizontal section through the center sills and the draft gear showing the ,gear in compressed position;

Fig. 3 is a section on the line 3-3 of Figi. 1;

Fig. 4 is a section on the line 4'-4 of Fig. 1

yFig..5 is a section on the line 5--5 of Fig. 1;

Fig. 6 is a vperspective View of one of the followers; I

Fig. '7 isaperspective view ofthe other follower;

Fig. 8 is r`akperspective View of one of the `wedge blocks;

I Fig.\.9 is alpersp'ective view of one of the wedge .iembers; and f Figi. 10 is a perspective view of the other wedge member.

The continual increase in the size or weight of the cars from time to time necessitates a corresponding increase in capacity for the draft gears. This increase in capacity becomes quite a problem due to the limited space available for the installation of the gear. For instance, an increase in the cross sectional area of the turns of the main resistance spring will increase the capacity of the gear, but this increase in the cross section of the turns means that with the conventional pitch the spaces between the turns will be reduced to such an extent that the spring will not have the proper travel, and, hence, will go solid before the opposed casings come in contact, thereby permanently injuring the spring. The space available for the reception ofthe gear is such that the gear must be so constructed as to accommodate the increase in size or weight of the `cars without an increase in the dimensions of the draft gear pocket. In the present invention the gear is so constructed that it not only has the dimensions of the conventional draft gear but also has sufficient capacity together with a proper amount of travel for both the springs and the gear casings to accommodate cars of different weights and capacities,

Referring now tothe drawings, the reference characters I0 and II designate the center sills of a railway car having the draft lugs I2 and I3 and the bufng lugs I4 and I5 forming the draft gear pocket I6, within which is mounted the draft gear II., as is usual in such constructions.

rIk'he draft gear comprises what forfconvenience of description will be termed the outer or forward follower `I8 and the inner or rear follower 19. These followers are hollow. The forward or outer follower I8 has both ends open while the rear or inner follower I9 preferably has its inner end closed as at 2l (see Figs. 1 and 6).

A follower plate 22 is preferably linserted Ybetween the outer end ofthe follower II8 and the draft lugs I2 and I3 which forms a closure for the outer end of the forward casing. The adjacent ends of these casings are rectangular. 'I'he forward casing has the depressed walls 23 at each corner of the gear forming the corner anges 24 which l are apertured for receiving bolts25 for limiting the expansion of the gear, as will presently appear. rIfhe rear follower I9 is also provided with the-depressed walls 26 that Vfornicorner fianges 2l which are also apertured for receiving the boilts 25. These bolts-extending `through the two sets of securingflanges 24 `and 21 are adapted to limit the separation of the gear when the same is not in position in the draft gear pocket. The depressed walls 23 at the four corners of the forward housing are preferably arranged on the arc of a circle, the diameter of which is substantially the same as the distance between the inner surfaces of the upper and lower walls of the gear whereby a spring 28 of maximum diameter may be received in the recess formed by said walls.

It will be noted that by depressing the walls 23 to form flanges, additional projections on the follower with a consequent reduction in the dimensions of the casings will not be necessary for the accommodation of the bolts 25, and, consequently, the spring 28 may be the maximum diameter that can be employed in the draft gear pocket. This is considered an important feature of applicants invention because it permits the use of a spring of the maximum diameter with a consequent increase in capacity.

The rear follower also has its intermediate corner walls 26 curved and depressed for accommodating the wedging mechanism, as will presently appear.

Suitable means are provided for yieldingly resisting the compression of the gear. In the form of construction shown, the forward casing I8 is provided with a pair of inwardly facing wedge faces 29 and 3| and the rear follower is similarly provided with inwardly facing wedge faces or inclined surfaces 32 and 33 at its forward end for cooperating with the wedge faces or inclined surfaces 29 and 3| for engaging wedging blocks, as will presently appear.

Each of the wedge faces on the two casings is curved transversely of the casing. These wedging faces are curved to afford clearance for the bolts 25. By curving these faces, weakening the housing at the intersection of the depressed walls and the securing lugs or flanges is also avoided.

Furthermore, from an inspection of Fig` 5, it will be apparent that the curved wedging faces together with the curved wedging elements will properly position those elements. This is considered an important feature of the invention since this arrangement will prevent skewing of the wedging elements, thereby insuring smooth operation of the gear on release as well as on compression.

A pair of wedge blocks 34 and 35 is provided for cooperating with the curved surface on the inner ends of the follower casings. Each of these blocks is provided with a pair of wedging faces 36 and 31 on its outer side and with a pair of wedging faces 38 and 39 on its inner side (see Fig. 8). The blocks are curved transversely to the gear to conform to the curvatures of the Wedging faces on the adjacent ends of the follower casings. A pair of wedging members or elements 4I and 42 (see Figs. 9 and 10) are provided for cooperating with the inner wedging faces 38 and 39 of the blocks 34 and 35, respectively.

The rear wedge member 4| is provided with `the inclined wedging faces 43 and 44 which are `curved transversely of the gear for engaging the corresponding curved wedge faces 38 of the "blocks 34 and 35. This block is provided with an 'axial opening 45 for receiving the retaining bolt 4B (see Fig. 2), as will presently appear. The opening 45 is countersunk at its outer end and is angular in form for receiving the head 41 of the bolt and preventing its rotation.

The forward wedge member 42 is likewise provided with wedging faces 48 and 49 at the sides thereof for engaging the wedge faces 39 on the Wedge blocks 34 and 35. The wedging faces 48 and 49 of the block 42 are also curved transversely of the gear for conforming to and frictionally engaging the Wedge face 39 of the block 34. The forward end of the block 42 is provided with an axial opening 59 which is countersunk as at 5| for providing a seat for a spring, as will presently appear.

Suitable means are provided for resiliently resisting the separation of the wedge members 4I and 42 when the gear is'compressed. In the form of construction shown, a plurality of springs are employed for this purpose. These springs are arranged concentrically on the retaining bolt 46.

In the form of construction selected to illustrate one embodiment of the invention, three concentrically arranged springs 52, 53 and 54 are employed. The inner spring 54 is adapted to seat in the recess or countersunk portion 5|, and the intermediate and outer springs 53 and 52, respectively, seat on the outer face of the wedge member 42. Since the springs have but little clearance between them, the inner spring 54 seated in the countersunk or recess 5| will assist in positioning said springs. Furthermore, since the outer spring 52 is adjacent to the curved walls 23, those walls will assist in centering the outer spring. The outer ends of the springs seat on a cap 55 secured on the outer end of the rod or bolt 46. To compensate for the depression 5|, the cap 55 may be provided with a hub portion 56 cn which the inner spring 54 is seated.

When the gear is assembled, the parts may be held in proper position by the bolts 25 at each corner of the gear. These bolts are adapted to engage the apertures in the corner anges of the two follower casings, as is clearly shown in Fig. 8 of the drawings. In order to increase the travel of the gear without decreasing its capacity, additional space is provided for accommodation of the springs. To provide this additional space, the wedge member 42 is provided with a recess 51 which is adapted to receive the corresponding projection 58 on the wedge member 4|. This recess and projection are arranged transversely to the wedging faces so as to not unduly weaken the wedge member 42. By means of this arrangement, a longer space is provided for the springs whereby springs having turns of greater cross sectional area and consequent greater capacity may be employed without decreasing the travel of the springs and without foreshortening the length of the wedging faces of the wedging members 4I and 42.

The casing I8 may, if desired, be provided with intermediate transverse ribs 59 which have their inner edges curved to conform to the curvature of the outerl spring 52 and assist in preventing buckling of said spring.

In the operation of the device, when the gear is compressed, either upon pull or upon buff, the follower casings are forced toward each other which through their adjacent wedging faces will force the wedge b-locks 34 and 35 inwardly and this in turn will tend to separate the wedge members 4| and 42 against the tension of the springs 52, 53 and 54. The friction of the wedge faces will absorb a great proportion of the force of buff or pull. Upon release of the pressure, the

springs will force the parts to their normal inoperative position, as shown in Figs. 1 and 4.

VUpon abnormal compression of the gear, the adjacent end of the casings will abuteach other,

and the shape of the top and side walls along with the curved walls of the casing will form a reinforced column that will prevent damage or distortion.

I claim as my invention:-

1. In combination, a pair of followers, a pair of curved wedge blocks within said followers, said blocks having inner and outer curved wedging faces, a pair of concave wedging faces on each follower engaging the outer curved faces of said blocks, a pair of opposed wedging members between said blocks on the center line of said gear and having convex wedging faces engaging the inner wedging faces of said blocks, one of said members having a projection engaging in a recess in the other member when said gear is in release position, a bolt extending axially through said members, a plurality of springs on the free end portion of said b-olt and a spring seat on the end of said bolt outwardly of said springs.

2. In a draft gear, a pair of follower casings having wedging faces on their meeting edges, a pair of wedging blocks engaging said faces, a pair of wedge members between Said blocks, one of said members having a projection engaging in a recess within the other of said wedge members when said gear is expanded, a bolt extending axially through said members and springs on said rod for resiliently resisting the separation of said members when said gear is compressed.

3. In a draft gear, a sectional casing comprising a pair of chambered followers provided at their adjacent edges with wedge faces, each of said faces being curved transversely to the axis of said gear, a pair of cooperating wedge blocks extending into the adjacent ends of said followers, each of said blocks being curved to conform to the curvature of the wedging faces on ,said followers, a pair of wedge elements, one in each casing having curved wedging faces engaging corresponding inner curved wedging faces of said blocks, said elements having their inner ends lapping when the gear is expanded, a bolt extending through said elements along the axis of said gear, and spring members on one end of said rod for resiliently resisting the separation tending axially through said elements and a spring seat on one end of said bolt and a plurality of springs between said seat and one of said elements, one of said elements having a counter-bore for receiving the head of said bolt and the other of said elements having a counterbore for receiving the inner end of one of said springs, said springs constituting the sole means for resiliently resisting the compression of the gear and for restoring the parts to normal position after compression.

5. In a draft gear, a pair of chambered followers having their adjacent ends provided with wedging faces, a pair of wedge blocks engaging said faces, a pair of opposed wedge members engaging said blocks, the adjacent portions of said members having cooperating interengaging portions that are adapted to engage when said gear is normally expanded, and means for resiliently resisting the separation of said members when said gear is compressed.

6. In a draft gear, a pair of followers having their adjacent ends provided with wedging faces, mechanism including spring pressed wedging means engaging said faces for frictionally resisting the compression of said gear, said means comprising a plurality of vwedge elements, certain of which has a recess and another a projection for engaging in said recess when said gear is compressed whereby said elements occupy a minimum of space and are provided With extended friction faces.

MARCHAND B. HALL. 

